The reality fashion-show genre has needed a makeover for some time since “Project Runway” migrated from Bravo to Lifetime and lost some of its luster in transit. NBC’s new competition show “Fashion Star,” premiering Tuesday night, at least deserves a look for its originality and conceptual pizzazz, attempting to do for the fashion show what “The Voice” has done for the singing show — which is to turn it on its head and try things a whole other way.

Each week, “Fashion Star’s” winning designers have their work snapped up by buyers from one of three department stores — Macy’s, H&M or Saks Fifth Avenue — which TV viewers can purchase online (or at select stores) the next day. That sounds like a wonderful idea to everyone, except, one imagines, the cheap laborers who’ll have to sew overtime to meet this speculative demand.

“Fashion Star’s” debut lasts 90 minutes but feels as though it’s about five hours. There are, gosh, probably 127 contestants, plus 10 or 12 mentor/judges and buyer/judges, plus one host — former supermodel Elle Macpherson.

When I double-checked, it turns out there are just 14 contestants and only three mentors and three buyers. It seems like more — and too many. It can also be difficult to understand the logistics behind what the contestants are winning from the store buyers — a licensing fee? A cut of sales?

Still, I like the show’s energy and pure meritocracy. Set before a live audience in an auditorium tricked out with dancers, flashy lights and club-banger pop songs, “Fashion Star” eats up a lot of time but doesn’t necessarily waste it. To keep pace, the show barely concerns itself with contestants’ back stories, personal demons and snit fits, wisely redirecting that sort of drama to a companion Web site for viewers who might care.

Instead, it’s mainly about clothes and more clothes — with an intense, almost post-recession focus on wearability and marketability. Say what you want about “Fashion Star” judge and mentor Jessica Simpson, she has made herself richer than you or I will ever hope to be with her successful foray into the fashion industry. Her savvy comes through quite clear on “Fashion Star,” which makes her just as much of an expert as John Varvatos, who joins her. Nicole Richie — a tamed, almost doyenne version of the tabloid caricature of yore — rounds off the panel.

Fates rest, however, with the three buyers, who vote with a brutal business sense for what they think will sell in their stores. On rare occasions a bidding war breaks out, but it’s more entertaining when all three display the cruel “NO OFFER” sign on their screens.

When a male Australian contestant tells a disapproving Simpson and Richie that he wouldn’t expect “girls” to understand his menswear concept, Simpson curtly reminds him: “You know there are two women buyers [sitting] behind you, right?”

Three guesses what happens to that dude.

Fashion Star

(90 minutes) premieres Tuesday at 9:30 p.m. on NBC.